SCIENCEIntroductory Unit:

The Nuts and Bolts of Doing Science

Scientific inquiry uses multiple interrelated processes to

investigate and explain the natural world.

Learning Target

• I can design, conduct, and analyze a scientific experiment. (9.1.1.2.1).

The Marble Lab

• Part 1:

Measure a property (characteristic) of a marble.

• Figure out something that nobody else has ever figured out.

• Make observations that nobody else ever has.• Be creative.

Only rule is you can’t throw the balls… you may roll them down ramps or bounce them, but NO THROWING.

The Marble Lab

• Part 2: Discussion • What type of data did you measure?• How reliable is it?

– How would you make it more reliable?

• Could you repeat this experiment and get the exact same results?– Could someone else repeat it and get the

same results?

The Marble Lab

• Part 2: Discussion • What did you write down?

– What should you have written down?

• What else is missing from your investigation?

The Marble Lab

• Part 2: Discussion • What is the purpose of doing this

investigation?– Limited Usefulness

• What are some possible uses for this knowledge?

• What would make this a more meaningful experiment, not just an investigation?– Relationship

Learning Target

• I can design, conduct, and analyze a scientific experiment. (9.1.1.2.1).

• This first unit is designed to get you to the point where you can do this successfully

Learning Target

SI1• I know that a scientific process exists for

testing and developing new concepts. (9.1.1.2.1)

Scientific Process

• “Although no single universal step-by-step scientific method captures the complexity of doing science, a number of shared values and perspectives characterize a scientific approach to understanding nature.”

Natl. Science Teachers Assoc.

<http://www.nsta.org/positionstatement&psid=22>

Science: Nuts and Bolts

• Different scientific disciplines explore their respective subject matter using a variety of related methodologies with common characteristics:– Need for evidence– Observations– Inference – Rational argument

… but no (2) scientists and no (2) disciplines perform science the exact same way.

− Skepticism − Peer review − Ability to repeat

• The main reason why scientists from different disciplines “do” science differently is because…

THEY HAVE TO.• Each discipline is unique and must deal

with different environments and constraints.– Constraint: limitations or restrictions

Science: Nuts and Bolts

Science: Nuts and Bolts

• Chemists can perform experiments

• Astronomy is based on extensive observations rather than experiments

• Paleontology: How do you perform an experiment to classify extinct creatures?

• Recall… Not all scientist perform their job the exact same way.

• There are thousands of different ways scientists approach “doing” science.

• There are several main types of scientific processes that they use for testing and developing new concepts.

Scientific Investigations

Scientific Investigations

Methods scientists might use to conduct an investigation…

• Research• Models• Experimentation

Scientific Investigations• Research

– Field Studies• Surveys

– Data/Results of Previous Scientists

• Modeling– There are many of different types of modeling

used. (more on this in a second)

• Experimentation– Scientific Method There isn’t only one method…

What’s a Model?

What’s a Model?

• Model Representation of an object or system

An analogy (or mental image). Scientific uses:

Help us understand the real object/systemTool to learn more about the object/system

Learning Target

SI2• I know the different types of modeling and

can determine which one may be best to use. (9.1.3.4.6)– Physical– Computer– Mathematical– Conceptual

Physical Model

Computer Model

Earthquake Simulation

Mathematical Model

Earthquake Data

Conceptual Model

The Rock Cycle

MODELS

BENEFITS LIMITATIONS• Models can be used for

the following:– Study objects that are

too small to see– Study objects that are

too large to see– Help explain the past

and the present– Help predict the future

• Scientists must realize the limitations of models, especially when reading the information obtained by them.− Can’t take all

details/variables into account

− Cost− Time

NO Model is ever perfect

Limitations of Models

• All models have limitations — no model can possibly explain every detail of a scientific phenomena. – if we wanted to predict the

distance we would need to travel from one side of the country of Nepal to the other, we could predict it using our “spherical Earth” model,

– We could add all the Himalaya mountain ranges in the world to our “spherical-Earth” model, this would make the model quite complex and defeat the utility of having a simple model to make useful predictions.

Practice

• What are 3 different ways that scientists “do” science?– Research– Modeling– Experimentation

Practice

• What are 4 main types of models?– Physical– Conceptual– Mathematical– Computer

Methods of ScienceResearch, Models & Experimentation can all be done following different methods…• Planned out step by step (Methodical)• Trial and Error• Accident

Methods of Science

• Trial & Error– Thomas

Edison tried hundreds of metals before tungsten finally worked

Methods of Science

• Accident– Henri Becquerel placed photographic plates

and radioactive ores in the same drawer leading us to an understanding of radiation

(The picture below is the image of Becquerel's photographic plate which has been fogged by exposure to radiation from uranium salts. The shadow of a metal Maltese Cross placed between the plate and the uranium salts is clearly visible.)

                                                                                                                                                           

(The picture is the image of Becquerel's photographic plate which has been fogged by exposure to radiation from uranium salts. The shadow of a metal Maltese Cross placed between the plate and the uranium salts is clearly visible.)

Methods of Science

• Accident– Wilhelm Röntgen later

accidentally discovers X-rays while studying cathode ray’s

(The picture below is the image of Becquerel's photographic plate which has been fogged by exposure to radiation from uranium salts. The shadow of a metal Maltese Cross placed between the plate and the uranium salts is clearly visible.)

                                                                                                                                                           

Recall…Learning Target

SI1• I know that a scientific process exists for

testing and developing new concepts. (9.1.1.2.1)

Scientific Inquiry

There isn’t only one method…

…but we need a place to start

We’ll start with what kicks off most investigations…

ObservationsWe are constantly making observations.

We do this both consciously and unconsciously.

• Our brains are constantly trying to make sense of our observations.

But…we must acknowledge that …

…Our senses can fool us, they are limited and prone to error.

Sometimes our brains fill in the details of an object that isn’t

really there

Observations

• What do you see?

Observations• Stare at the black dot. What happens?

Observation

Subway Train Illusion• http://twentytwowords.com/2013/05/21/

subway-optical-illusion-train-appears-to-be-moving-both-directions/

Observations

Spinning Dancer Illusion

http://www.youtube.com/watch?v=9CEr2GfGilw&feature=youtu.be&t=30s&safety_mode=true&persist_safety_mode=1&noredirect=1

Check out the Ames Illusion Room

• http://www.youtube.com/watch?v=vhoSqSHMIAc&safety_mode=true&persist_safety_mode=1

Observations• Which square is darker?

Observations• Which square is darker?

Observations

• Which square is darker, A or B?

• A and B are the same

Observations

• Here’s your proof:

Observations

Can you see the man’s face?

Observations

In science, you need to have sharp eyes and an even sharper brain

http://www.moillusions.com/

Observations

Making Observations…

Observations

What do you see?

Is it one face or two?

Observations

What do you see?

Is it an old woman?

Or is it a young woman

looking away?

Observations

How many

Faces are there

in this picture?

Observations

What do you see?

Is it a face or a man playing

a saxophone?

Observations

What do you see?

Is it a skull or two

Women?

Observations

A Duck?

A Rabbit?

Observations

• What do you see?

• An old man?

or• A young man?

Observations

A bird with a fish in its mouth?

A man fishing next to an island?

Observations

What do you see?

Observations

• Our brains are constantly trying to make sense of our observations.

But…we must acknowledge that …

…Our senses can fool us, they are limited and prone to error.

• Observations are when we collect information about the world using one of our five senses.

Learning Target

SI3• I know the difference between qualitative

and quantitative observations or data. (9.1.1.2.1)

Types of Observations/Data

• Quantitative– If it is in numerical form

ex: The desk is 1 meter tall.

• Qualitative– If it is not in numerical form

ex: The sky is blue.

Practice

• Several students wanted to see how fertilizer might help sunflowers grow. The grew some sunflowers with fertilizer and some without fertilizer. They then measured how tall the sunflowers grew.

• What type of observation did the students make when they recorded the growth of the sunflowers?A. Hypothetical

B. Inferential

C. Qualitative

D. Quantitative

Practice

• Several students wanted to know what the most common color of cars was so they sat out in front of the school and recorded the color of cars that went past in an hour

• What type of observation did the students make when they recorded the color of cars?A. Hypothetical

B. Inferential

C. Qualitative

D. Quantitative

Inference

• Inferences are when we make observations and apply prior knowledge, or past experiences to it.

Inference• Inferences are when we make

observations and apply prior knowledge, or past experiences to it.

• Our brains are constantly making inferences about the world around us.

• This can lead to biased or wrong answers. • PAUSE & THINK: There may be more

than one possible explanation– Try to stay away from making inferences

when you are really trying to make observations.

What do you OBSERVE?

What can you INFER?

Now what do

you think?

Infer what happened based on your observations.

Inference

ASSUMPTIONS:• Both “animals” were there at the same

time.– What is some evidence that might help with

time?• Overlapping tracks• Sharpness of edges on tracks

• Time is very difficult to deal with in science– How do we know how Earth evolved?

Inference

ASSUMPTIONS:• The scene unfolded left to right.

– can animals walk backwards?• The order that we discover evidence has

nothing to do with the actual order of events.

Scientific Inquiry

• We are trying to put a puzzle together without having the box to look at.

• We don’t have hardly any pieces yet.

• Every new piece we get gives us a better idea of what the finished picture should look like.

Mystery Boxes

What do you observe?

What do you infer is happening?

What is a prediction?• Prediction

Making an inference about a future event based on current evidence or past experience.

What do you predict will happen when...

Science - General

What is a hypothesis?• Hypothesis

A possible explanation for a set of observations or a possible answer to a scientific question

An educated guess about the way a process works that allows us to make predictions

An interpretation that explains results

Science - General

Process:• Observation (try to distinguish between

observations and inferences) leads to…• Hypothesis – explanation of why – leads

to…• Prediction – possible future event

We are trying to identify a pattern

Mystery Boxes

• Draw a picture of what you think it looks like inside of the box.

Science - General

• How do we ever know if we are right?

• What mysteries are we still trying to solve?– http://www.sciencemag.org/site/feature/misc/webfeat/125th/

• Who will tell us if we’ve solved them correctly?

Scientific Inquiry

• What do you observe (not Infer)

• So we observe something cool (or unique) so what?

We identify a pattern, so what?

What do we really want in science?

• Explain why stars twinkle

Scientific Inquiry

• Science – Generally starts with…• Observations –

Be aware of (or avoid) Inferences DON’T JUMP TO CONCLUSIONS – There may be more than one possible explanation

Lead to…• Hypothesis – Allows us to make …• Prediction –

Scientific Inquiry

• Prediction – – If the prediction proves to be correct

over and over again–Leads to a proper

• Explanation–Plausible answer to the original question

that experts agree on (nobody has proven wrong)

• Gets us closer to the Truth

• 3 Holes in a Bottle

Learning Target

SI4• I know the scientific inquiry process

(9.1.1.2.1)– Observation and form a question– Hypothesis and procedures– Conduct an experiment– Refine hypotheses and experiment again– Form a conclusion and communicate it

Show video http://www.youtube.com/watch?v=JH0_xC7q9tU&feature=youtu.be&safety_mode=true&persist_safety_mode=1

• Show video– http://www.youtube.com/watch?

v=JH0_xC7q9tU&feature=youtu.be&safety_mode=true&persist_safety_mode=1

• The Scientific Method / Experiment Components Handout

Scientific Inquiry“The” Scientific Method

- method used to answer questions or solve problems

Steps of a Scientific Method:– Purpose - Ask a Question – *Background Research (maybe)– Form a Hypothesis– Experiment - Test the Hypothesis– **Analyze the Results (Data)– **Draw Conclusions– Communicate Results

*not found in all versions of the Scientific Method **separate steps in some Scientific Methods

Question/Purpose• An unexplained event or observation• Ex.

• A question is a good “scientific” question if it is testable and measurable.

Observe vs. Infer Why does the water start to

freeze?

Youtube clips: Bottle freezing Freezing when pouring

Question/Purpose

Why did my pop spill?

Question/Purpose

• Try to get at the ultimate purpose or question.

• Example – Does anyone ever need a

shovel?– What do you want to do with the shovel?

– What you really need is the hole?

– Does anyone ever need a hole?

Question/Purpose

• Example– What do you want to put

in the hole?– Do you really want the

post?– Do you really want the

fence?– What you really want is

privacy

Question/Purpose

What causes the bumps in a dirt road?

Question/Purpose

What was the purpose of the investigation in the North Atlantic?

How Sensitive is our Climate to CO2

(not to drill holes in the ocean floor or studying mud)

Practice:

What is a testable question for each of the following observations.

1. The blue M&M’s taste the best.

2. Birds keep flying into my kitchen window.

3. I always get water in my ears when I go swimming.

The Hypothesis• A possible explanation for a set of observations or

a possible answer to a scientific question – An educated guess about the way a process

works that allows us to make predictions– Based on previous knowledge or experience.

Myth of the Hypothesis

• The role of hypothesis testing in scientific work is sometimes important, but not as important as non-experts seem to think.

• Maybe, Hypothesis should not be taught– Most scientists do not use them in the same

sense that they are taught in school– They don’t appear in scientific papers– They are not desirable because they will tend

to bias experimental design and analysis

Myth of the Hypothesis

• It is common to begin a series of experiments with one set of hypotheses, and to end with a completely different set. – Ex. Climate Change Expedition

• It is also common to conduct experiments with no clear hypotheses at all, just to explore the territory.– Climate Change Expedition could have

started with no hypothesis at all.

Myth of the Hypothesis

• Sometimes, we don’t even care if we ever come up with a hypothesis…

Newton said that he had no hypothesis at all as to the cause of gravity

The Hypothesis• Will help determine how the experiment will be

designed or conducted.• May not be the correct answer and it doesn’t need

to be.• When you write a hypothesis though, you need to

write what you think is going to happen and why you think that.

• You can’t just simply say that you think something is going to change.

• Scientific Method WS – Part 1: General – Hypothesis

Variables

• An event or condition the experimenter can change (vary), control, or look for.

• They may or may not play a role in solving the problem.

• Two types of variables: – Independent– Dependent

Independent Variable

• (AKA Manipulated Variable)

• Factor that is changed and/or managed by the experimenter on purpose.

• When you become independent of your parents/guardians, you will get to decide what to do.

• Be specific what EXACTLY is changing…– Type of fertilizer, amount of fertilizer, fertilizer vs.

no fertilizer

Independent Variable

• CONTROLLED EXPERIMENT: Only one independent variable should be changed at a time, all other factors must be constant.

– Constant: a variable within an experiment that you have to make sure does not change at all.

• Constants are the things that are the same in every trial of the experiment

Independent Variable

• You should only change one variable at a time so that you know that any changes that occur to the Dependent Variable are due only to that one variable you changed on purpose.

Practice• My niece noticed that one of the Hummingbird feeders at

our cabin was being used more than the others and she wanted to know why. Below are the details of what she did in 9 of her trials.

• Which 3 trials should she compare if she wants to know if it is the type of feeder that makes a difference?

A. E, G, and K

B. E, I, and L

C. F, K, and M

D. H, I, and J

Practice

• What variable is being tested if she compares trials G, I and K?A. Amount of

sugar.B. Location.C. Time of day.D. Type of

feeder.

• My niece noticed that one of the Hummingbird feeders at our cabin was being used more than the others and she wanted to know why. Below are the details of what she did in 9 of her trials.

Practice

• What is the source of error if you compare F, J and L?

• Uncontrolled experiment: You are changing the location & amount of sugar… you can only test 1 variable at a time

• My niece noticed that one of the Hummingbird feeders at our cabin was being used more than the others and she wanted to know why. Below are the details of what she did in 9 of her trials.

Dependent Variable

• (AKA Responding Variable)

• A factor which changes as a result of manipulating the independent variable.

• This is the unknown we hope to observe and/or measure.

• Be specific what EXACTLY is being measured…– Height of plant, diameter of stem, length of

leaves, weight of the plant

Practice:

1. If a scientist conducts an experiment to test the hypothesis that a new type of vitamin will prevent colds better than the old type.

What is the independent variable?

2. A scientist studies how effective a muscle building supplement is and checks bicep circumference daily.

What is the dependent variable in this experiment?

Practice:

3. People with a high exposure to UV light will have a higher frequency of skin cancer.

What is the independent variable?

4. A scientist studies how many days people can eat only carrots until they get sick.

What is the dependent variable in this experiment?

Variables and Hypotheses• When writing a hypothesis, it should include the

independent and dependent variables and include a reason why you think the way you do.

• “I think… if I change (Ind.Var.), then (Dep. Var.) will happen or be observed because....

• NOTE: A Hypothesis does NOT have to be in the form of an If…Then… Because statement.

• Example: “I think that the more Froot Loops you eat every morning the taller you’ll grow because since my niece started eating Fruit Loops she’s grown 2 inches in the last 2 months.”

Hypothesis

• Bad Hypothesis– If I run, then I will reach the finish line sooner because I

am faster.• Identify the I.V., the D.V. then come up with a good

scientific reasoning for why you think what you do.– Running is not your I.V.– Reaching the finish line is not your D.V.– Your reason cannot be the same as your I.V.

• Good Hypothesis– If I increase my speed, then I will decrease my time

because my increased force pushing on the ground will move me further each second.

Hypothesis

• Bad Hypothesis– If I change the fertilizer, the growth of the plant will

change because of the fertilizer.• You need to state if you think more or less

fertilizer will make the plants grow more or less.• Be specific on what your I.V. and D.V. are.• Again, you cannot use your I.V. as your reason.• Good Hypothesis

– If I increase the amount of fertilizer, then the height of the plant will increase because fertilizer has nutrients in it that the plants need to grow

Hypothesis

• Bad Hypothesis– Question: How does the time of day affect heart rate.– Hypothesis: If I run, then I will have a higher heart rate because

the Sun rises later in the winter than in the summer• The hypothesis has to relate to the question you are

investigating• Your sound scientific reasoning has to relate to the question

and explain why the I.V. will affect the D.V.• Good Hypothesis

– The number of beats your heart has per minute will be lower later in the day than it is earlier in the day because your heart will have tired out a little over the course of the day and will be weaker.

• Note: Your reason does NOT need to be correct… you just need to have sound scientific reasoning

Control

• An identical experiment in which the Independent Variable is left unchanged or normal.

• Used for comparing.Example:– Will fertilizer help a plant grow taller?– How do you know if the fertilizer helped?

Control

• The control group is the group within the experiment that the independent variable is NOT changed in.

• The experimental group is the group within the experiment in which the independent variable is being changed.

Control

• Need class discussion examples where they need to determine what the control group is… maybe from Design Detectives

Control

• Not all experiments will need a controlExample: How many licks does it take

to get to the center of a tootsie pop?

Example: How far do different size rocks roll down a hill?

Assumptions

• Assumptions are things that the person running the experiment cannot manage (regulate) and must just assume.

• Examples– If you do a survey, you can only assume

(hope) that everyone is being honest.– If you have people performing some task, you

can only assume (hope) they are trying their hardest.

• Design Detectives – Class WS – if needed• Scientific Method WS – Part 2: Variables

Marble Lab Prep:

• What is the testable question you want to investigate in your Marble Lab?

• What is your Independent Variable going to be?

• What is your Dependent Variable going to be?

• What is your hypothesis – include a reason

Experiment

• The hypothesis will help determine how the experiment will be designed or conducted.

• What would be a good experimental design for the following hypothesis…

“I think that darker surfaces will heat up faster than lighter surfaces because dark colors absorb heat easier.”

Experiment

• Once you have the basic idea for an experiment, you have to think hard about how you are going to perform it.

• You need to make sure that you’re results can only be affected by the independent variable.

• Constant: Any variable that you need to make sure doesn’t change in an experiment.

Experiment• Should include :

– a control (if necessary)• (different from a controlled experiment)

Experiment

• Then, all of the steps in your experiment need to be clearly stated in a set of procedures.

Procedures

• Draw it

&/or• Lego’s

Procedures

• Procedures are mostly for Others– To understand what you did– To be able to repeat what you did

Procedures

• Must correspond to the Question– Q: What causes the bumps in a dirt road?– Procedure can’t have you measure the distance

between ridges

• Must correspond to the Hypothesis– Hyp: I think the ridges are caused by rain because…– Procedure can’t have you testing the wind direction

Procedures

• Detailed– Make sure anyone could repeat your experiment exactly.

• ASSUME other people are IDOITS.– Don’t tell people to just time something. Tell them when to start the

timer and when to stop the timer.– Don’t tell people to just measure the height of a step… Tell them

HOW to measure the height of a step.• USE Diagrams whenever possible

• Don’t be Vague– Don’t tell people to pick a set of stairs to walk up, tell them exactly

how many stairs you walked up.– Don’t tell people to repeat 2 or 3 times… tell them exactly how many

times you repeated that part of the experiment

Procedures

• Everything you physically do in the experiment should be its own step.– Start the timer– Stop the timer– Record the data

• Each step needs to be numberedStep 3: Start the timer when you put the ice in the beaker.

Step 4: Stop the timer when the ice has completely melted.

Step 5: Record the data.

Procedures• Use “Repeat Steps ___ - ___” whenever

possible.Step 6: Repeat Steps 3 – 5 two more times

Step 7: Add a 50g mass to the cart

Step 8: Repeat Steps 3 – 6

Experiment• Should include :

– repetition (if possible)• It’s not always possible to repeat an experiment

Ex. Meteorites

Repetition

• The number of repetitions you choose is very important• Levels of Independent Variables: how many different

values of your I.V. are you going to test?– Ex. If you are going to test different types of fertilizer, how

many types are you going to test?• Trials: For each different level of independent

variable, how many trials are you going to run?– Ex. For each type of fertilizer, you are going to test it on 3

different plants.

• The # of Trials and # of Levels of I.V. should be repeat steps in your Procedures

Repetition

• How many times is enough?• 3 times is usually the minimum

• If it can’t be repeated, then what????

Repetition

• The experiment can and should be repeated many times by yourself and others and the same results obtained.

• The more it is repeated the more reliable the data becomes. – Reliability: the extent to which an experiment

yields the same results on repeated trials

Materials List

• Once your Procedures are done, you can write up a Materials List.

• The Materials List needs to…– Be in a List format– Include all of the materials you will need – Include Quantities – EVEN IF THE QUANTITY IS ONLY 1.

• Don’t need to include– Person to run the experiment– Paper/Pencil– Etc.

• Think of a cooking recipe… you don’t need to include in the materials list a cook, oxygen for the cook to breathe etc.

Procedures

Back to Procedures for a second…• Don’t include…

Step 1: Gather Materials

Step 98: Calculate Averages

Step 99: Graph Data

Step 100: Write Conclusion

This happens before the experiment and is really your Materials List

These happen after the experiment and are really part of Analyzing Results

Results and Data

• Results for individual trials should generally be the same– when results differ significantly, it is important to

investigate what may have caused such differences.

Sources of Error: • Human Bias – your brain led you down the wrong path

• Experimental Bias – – Measurement errors, – Equipment failures, – Uncontrolled variables – things that should have

been held constant but were not.

Scientific Inquiry“The” Scientific Method

- method used to answer questions or solve problems

Steps of a Scientific Method:– Purpose - Ask a Question – *Background Research (maybe)– Form a Hypothesis– Experiment - Test the Hypothesis– **Analyze the Results (Data)– **Draw Conclusions– Communicate Results

*not found in all versions of the Scientific Method **separate steps in some Scientific Methods

Learning Target

SI5• I can organize and analyze data for

reliability (bias, sources of error…) (9.1.3.4.4)

Results and Data

• Data: Information gathered during an investigation

Results and Data

2 Types Data:• Quantitative

– If it is in numerical form– measured

• Examples: size, temperature, time, weight

• Qualitative – If it is NOT in numerical form– descriptive, not measured

• Examples: color, smell, texture, sound

Data and Results

Tic Tac Toe – Using Data to Solve a Problem

Results and Data

• All observations and numerical results are recorded including calculations. Often data is organized in tables and graphs.

• Table - Lists observations and variables systematically.– Well organized data makes it easier to

analyze • Graph - Uses a grid to plot data points so

data can be easily compared and trends recognized.

Results and Data

• Well organized data makes it much easier to analyze data for reliability

• While recording data…

Results for individual trials should generally be the same– when results differ significantly, it is important

to investigate what may have caused such differences. • Sources of Error: Measurement errors, equipment

failures, or uncontrolled variables.

Results and Data

• Recognize that no experiment if perfect and that certain data points may be disqualified

Outlier

Practice

• Why do scientists use Tables and Graphs?A. It is required by the Scientific Method.

B. It makes it easier to organize data.

C. That’s what they were taught to do.

D. Their employer requires it.

Results and Data

• Well organized data makes it much easier to analyze data for reliability

• Graphing makes data even easier to understand and interpret.

Learning Target

SI6• I know the different types of graphs and

their parts ( 9.1.3.4.3)

• Types of Graphs Handout

• Types of Graphs and their Advantages and Disadvantages…

http://math.youngzones.org/stat_graph.html

Types of Graphs

Pie Chart or Circle Graph• Advantages:

– Easy to estimate values at a glance

– Great for percentages • Disadvantages:

– Cannot be used with a large number of categories

Types of Graphs

Pictograph • Advantages:

– Clarifies patterns and trends over time

• Disadvantages: – Pictures make it difficult to

determine exact number values

Types of Graphs

Line Plot • Advantages:

– Useful for seeing the existence of outliers

– Used to summarize a large data set

• Disadvantages: – Can’t be used with a large

number of categories or when range is too great

Types of Graphs

Stem and Leaf • Advantages:

– Easy to find the min. and max. values, and the mode

– Easy to find clusters or gaps in the data

• Disadvantages: – Unfamiliar to many people – Not useful for comparing

more than one population

Types of Graphs

Histogram – USED TO SHOW FREQUENCY

• Advantages: – Categories or numbers can be

compared at a glance – Easy to estimate values

• Disadvantages: – Does not provide exact values – Does not identify outliers

Types of Graphs

Bar Graph • Advantages:

– Shows distribution of data – Clusters or gaps in data easily

identified – Good for comparing groups

• Disadvantages: – Cannot be used to show how

something changes over time – Is not well suited for making

predictions

Types of Graphs

Line Graph • Advantages:

– Useful for determining if two sets of data are related

– Shows a trend or a change over time

• Disadvantages: – Harder to compare

categories or groups

Types of Graphs

Scatter Plot • Advantages:

– Categories are relatively easy to compare

– Can still see trends– Used for large data sets

• Disadvantages: – Reveals little about mean,

median or mode

Results and Data

• WE WILL almost ALWAYS USE LINE GRAPHS

• NO BAR GRAPHS!! (one exception)

Learning Target

SI7• I know how to interpret/analyze different

types of graphs (9.1.3.4.3)

Read Graphs Carefully

• Which stock will give the biggest profits?

• Pay attention to what’s on the x & y axis and what the scales are.

• Look at the actual data last.

Read Graphs Carefully• What’s wrong with this graph?

• The scale does not start at zero• It makes small differences look big

5.20 is not much different than 5.18

• Scientific Method WS – Part 3: Graphing

Learning Target

SI6 • I know the different types of graphs and

their parts ( 9.1.3.4.3)

Parts of a Graph

• What are some of the things you need to include on a graph?

• Graph Requirements Handout

Graph Requirements

YOU MUST PUT THE CORRECT VARIABLE ON THE CORRECT AXIS

Graph RequirementsY

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EXCEPTION

TIMENo matter if it is the Independent

Variable or the Dependent Variable

ALWAYS goes on the

X axis

Graph Requirements

Graph Requirements

Spacing on an axis must be the same

Spacing on x axis can be different than y axis

Try to use as much of the graph paper as possible

Graph Requirements

ALWAYS PLOT AVERAGES

Graph Requirements

NO Dot to Dot – Draw a Best Fit Line

Graph Requirements

Use a “proper” Title

It needs to be descriptive enough so people understand exactly what the graph is about

Graph Title

Practice• In an investigation, students wanted to find out if how tall a person is

affects how high they can jump. They test basketball players and the results are shown in the data table below.

• What should the graph look like to show a relationship between the two variables?

Practice• In an investigation, students wanted to find out if how tall a person is

affects how high they can jump. They test basketball players and the results are shown in the data table below.

• If a valid conclusion is to be reached, what assumption must be made?A. Players were all from the same team

B. Players tried to jump as high as they could

C. Results were all taken on a Tuesday

D. They all started on the floor

Learning Target

SI8• I can graph data appropriately (9.1.3.4.3)

• Graphing and Exp Design WS

Scientific Inquiry“The” Scientific Method

- method used to answer questions or solve problems

Steps of a Scientific Method:– Purpose - Ask a Question – *Background Research (maybe)– Form a Hypothesis– Experiment - Test the Hypothesis– **Analyze the Results (Data)– **Draw Conclusions– Communicate Results

*not found in all versions of the Scientific Method **separate steps in some Scientific Methods

Learning Target

SI9• I can use data to draw a conclusion…

– that supports or rejects a hypothesis, – describes errors in the exp. design or – identifies further questions (9.1.3.4.4)

Conclusion

• Conclusion: A judgment or generalization based on observations and/or data gathered. – Summary of what you learned in your investigation

Includes (3) possible things…

1. Has to refer to the hypothesis and support or reject it.– You can’t just say whether the hypothesis is right or

wrong, you need to… 1. State if the hypothesis was supported or rejected2. Describe how your results were similar to or

different than your original hypothesis

Conclusion

Example: • My hypothesis was supported, the more sleep

students get the better they do on tests. • My hypothesis was NOT supported, (or it was

rejected) taller players cannot necessarily jump higher.

Includes (3) possible things…

2. May/Should also suggest new or refined questions or hypotheses.

3. May include Possible Sources of Error

Conclusion

• What if your conclusion does NOT match your hypothesis?– Repeat the experiment, maybe you did

something wrong.• Revise the experiment

– Refine your hypothesis and start the whole investigation over.

– Nothing… maybe you learned as much from the wrong hypothesis as you would have from the right hypothesis• Ex. You thought Fertilizer A would be better than

Fertilizer B

Results and Data

• What if your conclusion does NOT match the accepted results of others?

• If your overall results don’t match the generally accepted results of others…– Re-run your experiment – Check your experiment… there is a good chance that

you did something wrong in the design or execution of your experiment

Learning Target

SI10• I can identify weaknesses in conclusions

by examining data and experimental evidence. (9.1.1.2.3)

• Scientific Method WS – Part 4: Conclusions

• Let it Snow WS (if needed)

Scientific Inquiry“The” Scientific Method

- method used to answer questions or solve problems

Steps of a Scientific Method:– Purpose - Ask a Question – *Background Research (maybe)– Form a Hypothesis– Experiment - Test the Hypothesis– **Analyze the Results (Data)– **Draw Conclusions– Communicate Results

*not found in all versions of the Scientific Method **separate steps in some Scientific Methods

Scientific Inquiry

• Science – Generally starts with…• Observations –

Be aware of (or avoid) Inferences

Lead to…• Hypothesis – Allows us to make …• Prediction –

Scientific Inquiry

Ultimately, we are trying to identify a pattern

What we discover will fall into one of the following “Products of Science”• Scientific Model• Scientific Principle• Scientific Law• Scientific Theory

Our results will be ADDED TO a model, principle, law or theory that already exists or we may have discovered something completely NEW.

Learning Target

SI11• I know the difference between law, theory

and hypothesis. (9.1.1.1.2)

The Nature of Science

• Scientific Law Statement of Fact Tells how things work in nature. Must be simple and universal (true everywhere) Governmental Laws say this is what you are suppose

to do, if you break the law there are consequences In Science if a Law is broken, then the Law is no longer

valid

Summary of many experimental results and observations.

Does NOT explain how a process takes place

EXAMPLES of SCIENTIFIC LAWS• Ohm’s Law

– I = V/R– Relationship between current,

voltage, and resistance– Named after Georg Ohm

• Newton’s Law s– Objects at rest/motion stay at

rest/motion until a force acts on it.

– Objects will accelerate in the direction of the force (F = M*A).

– Action-Reaction forces (equal and opposite)

• Law of Segregation– For any pair of characteristics

there is only one gene in a gamete even though there are two genes in ordinary cells.

– Founder – Gregor Mendel

• Ideal Gas Law– Combination of Charles's and

Boyle’s gas laws.– Formula: pV = nRT– Relates pressure,

temperature, and volume of gasses

• Universal Law of Gravitation, • Laws of Conservation of Mass & Energy…

Products of Science

• Scientific Principle

a general statement, similar to a Law, only more specific

• Ex. The principle of uniformitarianism, principle of original horizontality, principle of superposition, principle of faunal succession

Products of Science

Theory• A clear and consistent accepted

explanation of known observations • Ties together a group of related observations• Theories build upon prior scientific

knowledge and discoveries. • There is a gradual development and

improvement of any scientific theory over time.

A Theory is like a Car

• A car has many moving parts that work together.• It is a complex piece of machinery. • Sometimes, improvements are made to one or

more of its parts…Ex. A better set of sparkplugs might replace an older set

… But the function of the automobile as a whole remains unchanged.

• A theory is like the automobile. Components of it can be changed or improved upon, without changing the overall truth of the theory as a whole.

SCIENTIFIC THEORY

• Theories may be supported by scientific evidence at the time but may be incorrect. – Evidence may change with

time; better technology– Example: Plate Tectonics

• There is a gradual development and improvement of any scientific theory over time.

• Investigation is a key when creating theories.

EXAMPLES of SCIENTIFIC THEORIES

• Big Bang Theory– The universe has

expanded from hot, dense, gaseous conditions.

• Tectonic Plate Theory– The surface of the earth is

composed of tectonic plates, which move slowly.

• Atomic Theory– All matter is made up of

atoms.

• Theory of Matter and Energy– Matter and Energy are

always conserved.

• Cell Theory– Cells form the foundation,

the basic unit of all living organisms.

• Theory of Evolution– All life on earth evolved

from simple forms.

Theory vs. Hypothesis

• Hypothesis is a possible explanation• Theory is an accepted explanation

Products of Science

Laws and Theories…• Allow predictions to be made about how

an object or system will behave under a wide range of conditions.

Science Products

Laws, Theories etc… No one around to ask if its right or

wrong Hard to prove anything right (Facts are

hard to come by) Up to other scientist to prove it wrong –

Peer Review

Accept what works,

Reject what doesn’t

Practice

• What is the difference between a hypothesis and a law?A. A hypothesis is a possible explanation, a law is a

factual statement.

B. A hypothesis is based on one single observation, a law is based on many observations.

C. A law always has to be followed, a hypothesis only has to be true most of the time.

D. A law applies everywhere in the universe, a hypothesis only applies here on Earth.

Practice

• What is a theory?A. A possible explanation to what many people

have observed

B. A statement of fact that is always true

C. An accepted explanation based on the results of many different scientists.

D. What scientists believe to be true and are working on proving.

• Hypothesis vs. Law vs. Theory WS

Learning Target

SI12• I can design, conduct, and analyze a

scientific experiment. (9.1.1.2.1).

• You should now be able to do this successfully

• Marble Lab Requirements